Testing with the use of a large-size device, in air

This test procedure uses a pneumatic tyre having a track width of 80 mm and a tyre pressure of 600 kPa. 

Before the test, the specimens are subjected to a conditioning run for 1000 loading cycles at a temperature between 15°C and 25°C. It is highlighted that one loading cycle is two passes (outward and return) of the loaded wheel. 

After the conditioning run, the specimens are conditioned for 12-16 h at the selected test temperature applying 600 kPa wheel pressure, and afterwards, the 5 kN testing rolling load is applied for 30,000 cyclic loadings with 1 Hz (1 s) frequency, along the centre line of the specimen. 

The rut depth is measured at 15 predetermined locations. The test is completed after the required number of cycles is reached (30,000) or if the mean rut depth measured at the 15 locations exceeds 18 mm. 

The test temperature is usually 60°C or 50°C. The test temperature is measured both in the ventilated enclosure and within the specimen. The temperature within the specimen should be maintained at 2°C from the selected test temperature. 

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